Electric-furnace heating unit



1,626,656 May 3 1927' J. c. wooDsoN Y ELECTRIC FURNAGE HEATING UNITFiled D60. '7, 1923 Patented May 3, 1927.

UNITED STATES IGATENT OFFICE.

JAMES C. WOODSON, 0F EAST PITTSBURGH, PENNSYLVANIA, ASSIGNOR TO WESTING-HOUSE ELECTRIC & MANUFACTURINGy COMPANY, A CORPORATION OF PENNSYL-VANIA.

ELECTRIC-FURNACE HEATING UNIT.

My invention relates to electric heating devices and particularly toheating units for electric resistance furnaces.

The object ot my invention is to provide a self-contained electricheating unit, of relatively small and compact construction and ofrelatively high heat capacity, that shall have both terminal members ofthe heating unit extending therebeyond at both ends thereof.

In practicing my invention, 1 provide a. pair of spaced resistormembers, each comprising a plurality of end connected, return bent, andsubstantially straight convolutions located a short distance apart andhavingtheir rounded end portions located in a plurality of spacedpockets provided inthe refractory supporting members.

Intermediate, refractory supporting bars, having co-operating spacedgrooves in their-adjacent surfaces are provided intermediate the ends ofthe convolutions and all of the refractory members are supported by anassembled metal skeleton frame. At each side of the heating unit thereextends a. ielatively heavy rod or bar of metal to which the respectiveends of the resistor member are electrically connected.

In the single sheet of drawings,

Figure 1 is a view, partially in side elevation and partially insection, of an electrical heating unit embodying my invention,

Fig. 2 is a view, partially in end elevation and partially in sectiontherethrough, taken on the line II-II of Fig. 1, and

Fig. 3 is a view, in section therethrough, taken on the line III-III ofFig. 1.

An electric heating unit 11 comprises a pair of vresistor members 12each made ofv metal wire or rod of relatively heavy crosssection andpreformed to comprise a plurality of return-bent and end connectedconvolutions lying in a single plane.

At each end of the heating unit, there is provided a refractory bar ormember 13 that may be substantially rectangular in crosssection and thatis provided With a plurality of sets of spaced and aligned pockets 111in one face thereof, the dimenslons of each pocket being such that itwill receive one of the rounded end turns of the respective resistormembers 12.

The adjacent sets of pockets may be located in staggered relationrelatively to each other, as is illustrated in Fig. 2, in order that theindividual straight convolutions of the adjacent resistor members 12shall be located in' staggered relation, thereby permitting of theunobstructed dissipation of radiation of the heat of the rear resistormember 12 past the front resistor member 12 of the same heating unit.

If the length of the convolutions is relatlvely great, or if the lateralarea of the cross-section ofthe resistor members 12 is relatively small,I may employ intermediate refractory bars in order to. preventaccidental contact of the adjacent convolutions at the intermediateportions of their length. I may employ two outer bars 15, of suitablerefractory electric-insulatin material having a plurality of spaced,sustantially semicircular, grooves in one face and an intermediate bar16 having a plurality of spaced and substantially semicircular groovesin each face co-operating with the grooves in the members 1-5 to form a.plurality of spaced grooves 17, of substantially circular form, in theassembled members, through which the convolutions of the resistor'members 12 may loosely entend. v

- Side members 18, of substantially channel section and made of ja.substantially nonoxidizable metal, such as nichrome, are provided intowhich the ends of the refractory members 13 may fit to be therebysupported in their proper operative positions. End members 19 that maycomprise bars or elongated plates of al substantially nonoxidizableinet-al are suitably bolted at their ends to the end portions of themembers 18 into which they fit in order to prevent any til) relativemovement thereof during the operaltion of the heatingy unit.

A plurality of spaced rods 21 of relatively large lateral section and ofa suitable nonoxidizable material such as nichrome are located at therespective sides of the resistor members and extend through suitableopenings in the members 13 and in the member 16 of refractoryelectric-insulating material.

Bushings 22 may be provided in the end members 19 to suitably insulatethe terminal rods 21 therefrom. One of the ends of each of the resistormembers 12 is electrically connected to one of the terminal rods 21-byany suitable or desired means to effect a secure electrical connection,'that will withstand the relatively severe operating conditions of sucha heating unit.

The terminal rods 2l eXtend through the end members 19 and any suitabledistance therebeyond in order that both terminal members of the heatingunit may be provided at each end thereof, thereby permit- 'ting ofconnecting supply circuit conductors thereto at either end thereof, orpermitting any desired connection at either end to other adjacentlylocated heating units.

Various modifications and changes may be made Without departing from thespirit and scope of the invention, I desire, therefore, that only suchlimitations shall be placed thereon as are imposed b v the prior art.

I claim as my invention:

1. In an electric heating unit, in combination, a plurality of resistormembers located in parallel planes and in staggered relation relativelyvto each other, refractory spacing and supporting members for the endsand an intermediate portion of said resistor members, and a metal framefor holding said refractory members in their proper operative positions.

2. In an electric heating unit, in combination, a metal frame,refractory members at the ends of said frame, each having a spacedplurality of sets of alined and spaced pockets in the inner facethereof, a plurality of `resistor members, each comprising a pluralityof return-bent convolutions lying '1n one plane, the return bent endportions bein located in said spaced pockets, and a pair spaced4terminal members for said resistors supported by said refractorymembers and extending therebeyond at both ends of the unit.

3. In an electric heating unit, in combination, a metal frame,refractory members'at the ends of said frame, each having a spacedplurality of sets of alined and spaced pockets in the inner facethereof, a plurality of resistor members, each comprising a plurality ofreturn-bent convolutions lying in one plane, the return-bent endportions being located in said spaced pockets and a pair of terminalrods, each having one end of each resistor member electrically connectedthereto, and extending through and beyond said heating unit at each endthereof t0 provide a terminal member for each end of said resistormembers at each end of said unit.

4. In an electric heating unit, in combination, a metal frame,refractory members at each end of said frame, each having a spacedplurality of sets of alined and spaced pockets in the inner face thereofand the pockets in the respective sets being staggered relativel to eachother., a plurality of resistor mem rs, each comprising a plurality ofreturn bent convolutions lying in one plane, the return bent endportions being located in sai-d pockets and serving to maintain saidrefractory members in roper spaced relation in said frame, and) a pairof spaced terminal members for said resistors supported by saidrefractory members and extending therebeyond at each end of the frame.

In testimony whereof, I have hereunto subscribed my name this 20th dayof November, 1923.

JAMES C. WOODSON.

